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20#include <linux/idr.h>
21#include <linux/device.h>
22#include <linux/err.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/posix-clock.h>
27#include <linux/pps_kernel.h>
28#include <linux/slab.h>
29#include <linux/syscalls.h>
30#include <linux/uaccess.h>
31
32#include "ptp_private.h"
33
34#define PTP_MAX_ALARMS 4
35#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
36#define PTP_PPS_EVENT PPS_CAPTUREASSERT
37#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
38
39
40
41static dev_t ptp_devt;
42static struct class *ptp_class;
43
44static DEFINE_IDA(ptp_clocks_map);
45
46
47
48static inline int queue_free(struct timestamp_event_queue *q)
49{
50 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
51}
52
53static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
54 struct ptp_clock_event *src)
55{
56 struct ptp_extts_event *dst;
57 unsigned long flags;
58 s64 seconds;
59 u32 remainder;
60
61 seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
62
63 spin_lock_irqsave(&queue->lock, flags);
64
65 dst = &queue->buf[queue->tail];
66 dst->index = src->index;
67 dst->t.sec = seconds;
68 dst->t.nsec = remainder;
69
70 if (!queue_free(queue))
71 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
72
73 queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS;
74
75 spin_unlock_irqrestore(&queue->lock, flags);
76}
77
78static s32 scaled_ppm_to_ppb(long ppm)
79{
80
81
82
83
84
85
86
87
88
89
90
91
92 s64 ppb = 1 + ppm;
93 ppb *= 125;
94 ppb >>= 13;
95 return (s32) ppb;
96}
97
98
99
100static int ptp_clock_getres(struct posix_clock *pc, struct timespec *tp)
101{
102 tp->tv_sec = 0;
103 tp->tv_nsec = 1;
104 return 0;
105}
106
107static int ptp_clock_settime(struct posix_clock *pc, const struct timespec *tp)
108{
109 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
110 struct timespec64 ts = timespec_to_timespec64(*tp);
111
112 return ptp->info->settime64(ptp->info, &ts);
113}
114
115static int ptp_clock_gettime(struct posix_clock *pc, struct timespec *tp)
116{
117 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
118 struct timespec64 ts;
119 int err;
120
121 err = ptp->info->gettime64(ptp->info, &ts);
122 if (!err)
123 *tp = timespec64_to_timespec(ts);
124 return err;
125}
126
127static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx)
128{
129 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
130 struct ptp_clock_info *ops;
131 int err = -EOPNOTSUPP;
132
133 ops = ptp->info;
134
135 if (tx->modes & ADJ_SETOFFSET) {
136 struct timespec ts;
137 ktime_t kt;
138 s64 delta;
139
140 ts.tv_sec = tx->time.tv_sec;
141 ts.tv_nsec = tx->time.tv_usec;
142
143 if (!(tx->modes & ADJ_NANO))
144 ts.tv_nsec *= 1000;
145
146 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
147 return -EINVAL;
148
149 kt = timespec_to_ktime(ts);
150 delta = ktime_to_ns(kt);
151 err = ops->adjtime(ops, delta);
152 } else if (tx->modes & ADJ_FREQUENCY) {
153 s32 ppb = scaled_ppm_to_ppb(tx->freq);
154 if (ppb > ops->max_adj || ppb < -ops->max_adj)
155 return -ERANGE;
156 err = ops->adjfreq(ops, ppb);
157 ptp->dialed_frequency = tx->freq;
158 } else if (tx->modes == 0) {
159 tx->freq = ptp->dialed_frequency;
160 err = 0;
161 }
162
163 return err;
164}
165
166static struct posix_clock_operations ptp_clock_ops = {
167 .owner = THIS_MODULE,
168 .clock_adjtime = ptp_clock_adjtime,
169 .clock_gettime = ptp_clock_gettime,
170 .clock_getres = ptp_clock_getres,
171 .clock_settime = ptp_clock_settime,
172 .ioctl = ptp_ioctl,
173 .open = ptp_open,
174 .poll = ptp_poll,
175 .read = ptp_read,
176};
177
178static void delete_ptp_clock(struct posix_clock *pc)
179{
180 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
181
182 mutex_destroy(&ptp->tsevq_mux);
183 mutex_destroy(&ptp->pincfg_mux);
184 ida_simple_remove(&ptp_clocks_map, ptp->index);
185 kfree(ptp);
186}
187
188
189
190struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
191 struct device *parent)
192{
193 struct ptp_clock *ptp;
194 int err = 0, index, major = MAJOR(ptp_devt);
195
196 if (info->n_alarm > PTP_MAX_ALARMS)
197 return ERR_PTR(-EINVAL);
198
199
200 err = -ENOMEM;
201 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
202 if (ptp == NULL)
203 goto no_memory;
204
205 index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
206 if (index < 0) {
207 err = index;
208 goto no_slot;
209 }
210
211 ptp->clock.ops = ptp_clock_ops;
212 ptp->clock.release = delete_ptp_clock;
213 ptp->info = info;
214 ptp->devid = MKDEV(major, index);
215 ptp->index = index;
216 spin_lock_init(&ptp->tsevq.lock);
217 mutex_init(&ptp->tsevq_mux);
218 mutex_init(&ptp->pincfg_mux);
219 init_waitqueue_head(&ptp->tsev_wq);
220
221
222 ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp,
223 "ptp%d", ptp->index);
224 if (IS_ERR(ptp->dev))
225 goto no_device;
226
227 dev_set_drvdata(ptp->dev, ptp);
228
229 err = ptp_populate_sysfs(ptp);
230 if (err)
231 goto no_sysfs;
232
233
234 if (info->pps) {
235 struct pps_source_info pps;
236 memset(&pps, 0, sizeof(pps));
237 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
238 pps.mode = PTP_PPS_MODE;
239 pps.owner = info->owner;
240 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
241 if (!ptp->pps_source) {
242 pr_err("failed to register pps source\n");
243 goto no_pps;
244 }
245 }
246
247
248 err = posix_clock_register(&ptp->clock, ptp->devid);
249 if (err) {
250 pr_err("failed to create posix clock\n");
251 goto no_clock;
252 }
253
254 return ptp;
255
256no_clock:
257 if (ptp->pps_source)
258 pps_unregister_source(ptp->pps_source);
259no_pps:
260 ptp_cleanup_sysfs(ptp);
261no_sysfs:
262 device_destroy(ptp_class, ptp->devid);
263no_device:
264 mutex_destroy(&ptp->tsevq_mux);
265 mutex_destroy(&ptp->pincfg_mux);
266no_slot:
267 kfree(ptp);
268no_memory:
269 return ERR_PTR(err);
270}
271EXPORT_SYMBOL(ptp_clock_register);
272
273int ptp_clock_unregister(struct ptp_clock *ptp)
274{
275 ptp->defunct = 1;
276 wake_up_interruptible(&ptp->tsev_wq);
277
278
279 if (ptp->pps_source)
280 pps_unregister_source(ptp->pps_source);
281 ptp_cleanup_sysfs(ptp);
282 device_destroy(ptp_class, ptp->devid);
283
284 posix_clock_unregister(&ptp->clock);
285 return 0;
286}
287EXPORT_SYMBOL(ptp_clock_unregister);
288
289void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
290{
291 struct pps_event_time evt;
292
293 switch (event->type) {
294
295 case PTP_CLOCK_ALARM:
296 break;
297
298 case PTP_CLOCK_EXTTS:
299 enqueue_external_timestamp(&ptp->tsevq, event);
300 wake_up_interruptible(&ptp->tsev_wq);
301 break;
302
303 case PTP_CLOCK_PPS:
304 pps_get_ts(&evt);
305 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
306 break;
307
308 case PTP_CLOCK_PPSUSR:
309 pps_event(ptp->pps_source, &event->pps_times,
310 PTP_PPS_EVENT, NULL);
311 break;
312 }
313}
314EXPORT_SYMBOL(ptp_clock_event);
315
316int ptp_clock_index(struct ptp_clock *ptp)
317{
318 return ptp->index;
319}
320EXPORT_SYMBOL(ptp_clock_index);
321
322int ptp_find_pin(struct ptp_clock *ptp,
323 enum ptp_pin_function func, unsigned int chan)
324{
325 struct ptp_pin_desc *pin = NULL;
326 int i;
327
328 mutex_lock(&ptp->pincfg_mux);
329 for (i = 0; i < ptp->info->n_pins; i++) {
330 if (ptp->info->pin_config[i].func == func &&
331 ptp->info->pin_config[i].chan == chan) {
332 pin = &ptp->info->pin_config[i];
333 break;
334 }
335 }
336 mutex_unlock(&ptp->pincfg_mux);
337
338 return pin ? i : -1;
339}
340EXPORT_SYMBOL(ptp_find_pin);
341
342
343
344static void __exit ptp_exit(void)
345{
346 class_destroy(ptp_class);
347 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
348 ida_destroy(&ptp_clocks_map);
349}
350
351static int __init ptp_init(void)
352{
353 int err;
354
355 ptp_class = class_create(THIS_MODULE, "ptp");
356 if (IS_ERR(ptp_class)) {
357 pr_err("ptp: failed to allocate class\n");
358 return PTR_ERR(ptp_class);
359 }
360
361 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
362 if (err < 0) {
363 pr_err("ptp: failed to allocate device region\n");
364 goto no_region;
365 }
366
367 ptp_class->dev_groups = ptp_groups;
368 pr_info("PTP clock support registered\n");
369 return 0;
370
371no_region:
372 class_destroy(ptp_class);
373 return err;
374}
375
376subsys_initcall(ptp_init);
377module_exit(ptp_exit);
378
379MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
380MODULE_DESCRIPTION("PTP clocks support");
381MODULE_LICENSE("GPL");
382
